Evolutionary developmental biology (evo–devo) has become an established field of research, especially since the spectacular results obtained in the 1990s regarding cross-species molecular homologies of (Hox) genes acting early during embryogenesis in insects, vertebrates, and beyond. Amundson summarizes some of these results, which justify a central assertion of evo–devo, namely that one must understand how bodies are built in order to understand how the process of building bodies can be changed, that is, how evolution can occur. But Amundson's book is not about these discoveries, but about the history of evo–devo.